Aligned slip well tool



June' 19, 1956 R. c. BAKER 2,751,018

Filed Feb. 5, 1953 J2 v 17 3; INVENTOR.

'' EEUEEN C. BAKER,

BY a? 1% MJMW A TTOQNE'YJ United States Patent ALIGNED SLIP WELL TOOLReuben C. Baker, Coalinga, Calif., assignor to Baker Oil gools, Inc.,Los Angeles, Calil., a corporation of Caliornia Application February 3,1953, Serial No. 334,783 Claims. (Cl. 166-217) The present inventionrelates to subsurface well tools, and more particularly to well toolsembodying segmental slips that are expanded outwardly against the wallsof well conduits, such as well casing disposed in well bores.

Certain kinds of subsurface well tools utilize segmental slips foranchoring them in a well conduit, such as a well casing. The slipsoccupy a normal or initial retracted position, from which they areexpanded outwardly into engagement with the wall of the well conduit.During their outward expansion, the slip segments may not remain intransverse alignment, and, if they become dis aligned, they will engagea companion expander in such manner as to force the tool 011 centerwithin the well conduit, or tilted out of a desirable coaxial positionwith the well conduit.

Accordingly, an object of the invention is to provide an improved devicefor maintaining segmental slips transversely aligned, all in a positivemanner. Another object of the invention is to provide a transversealigning device for segmental slips which are initially retained inretracted position, in which the aligning device a well packer A of thegeneral type illustrated in United States Patent No. 2,121,051. Thiswell packer is designed to be lowered through a well casing B on thelower end of a tubular string C, with the packer parts initially ornormally held in retracted position. The packer includes a main body 10that can be secured to the lower end of the tubular string C by means ofa suitable lefthand threaded connection 11. This body carries a set ofupper annular segmental tapered slips 12 adapted to be moved intoengagement with the casing B by an upper conical expander 13 initiallysecured to the body 10 by one or more shear screws 14. The upper slips12 are retained initially in retracted or ineifective position by shearscrews 15 securing them to the conical expander, the upper ends of theslips 12 engaging the lower surface of an abutment member or ring 16threaded on the main body 10. Suitable guide means are provided betweenthe abutment member 16 and the slip segments 12, to insure the properarcuate disposition of the slip segments with respect to each otherduring their outward expansion into engagement with the well casing B.As shown, longiresists the longitudinal movement of the slips upon theirrelease for outward expansion.

A further object of the invention is to provide a transverse aligningarrangement for segmental slips, which not only maintains the slips intransverse alignment during their outward expansion into engagement withthe well will now be described in detail, for the purpose ofillushitting the general principles of the invention; but it is to beunderstood that such detailed description is not to be taken in alimiting sense, since the scope of the invention isbest defined by theappended claims.

Referring to the drawings:

view of a well tool, with its parts disposed in their initial ornormally retracted position;

Fig. 2 is a view similar to Fig. l, disclosing the well the casing;

Fig. 3 is a view similar to Fig. 2, showing the well tool fully set inthe well casing;

Fig. 4 is an enlarged fragmentary, longitudinal section,

disclosing a relative condition that some of the parts may out of thehousing 24 permits the ball 35 to engage its assume; Fig. 5 is across-section, taken along the line 5-5 on Fig. l; 1

Fig. 6 is a cross-section, taken along the line 6-6.on F g: I

tudinally extending pins 17 are secured in the lower portion of theabutment ring 16, which project into generally radial, transverse slots18 formed in the upper portions of the segments 12.

A lower set of annular segmental slips 19 is initially held in retractedposition by attaching them to a lower conical expander 20 through theagency of shear screws 21. This lower expander is initially held ininefiective position by shear screws 22 threaded into the body 10. Thelower ends of the lower slips 19 engage an abutment consisting of aflanged portion 23 at the lower end of the body 10 and a valve housing24 threaded on the flange.

Y A packing sleeve 25 of synthetic or natural rubber is positioned onthe body 10 between and suitably secured to the ends of the expanders13, 20. This sleeve is retained initially in retracted position freefrom contact with the casing wall, but is capable of being expanded intoengagement therein. As described hereinafter, the upper segmental slips12 are released from their normally retracted position and expandedoutwardly by pumping fluid under pressure into the packing sleeve 25through the body ports 26 to inflate the sleeve. For the purpose ofpreventing leakage from the pocking sleeve 25 during this inflatingoperation, its end portions are provided with E opposed annular lipseals 27 which engage the periphery of the body 10 in leakproof fashion.

It is to be noted that the coengaging surfaces 28, 29 on the upperconical expander 13 and upper slips 12 taper in an upward and inwarddirection, so that relative longitudinal movement of the upper expander13 within the slips 12 will move the latter outwardly against the casingB. In like manner, the lower expander 20 and lower slips 19 have theircoengaging surfaces 30, 31 tapering in a downward and inward direction,in order that relative longitudinal movement of the lower expanderwithin the Figure 1 is a longitudinal sectional and'side elevational kSlips 19 will Shift the latter radially Outward into engagement with thecasing B.

The valve housing 24 contains a tripping ball seat 32 that is heldinitially therewithin by a shear screw 33.

tool in a well casing, and parts thereof expanded against This seat hasan upstanding arm 34 for holding a buoyant back pressure ball valve 35in ineflective position against the interior of the housing 24 toprevent its upward movement and seating against a valve seat 36 at thelower end of the main packer body 10. Removal of this arm 34 by pumpingthe tripping ball seat unit 32 cooperable seat 36 whenever upward orreverse flow of fluid through the body 10 tends to occur. I The packervA is run in the casing B to the desired setting point, after which atripping ball 37 may be low- The invention is disclosed in the' drawingsas ap plie'dto 'ered or pumped down through the tubular 'string' C intoPatented June 19, 1956 seating engagement with the tripping ball seat32. Such engagement prevents any further downward passage of fluidthrough the well packer A and allows the pressure of the fluid withinthe tubular string C and packer body to be increased. This fluid underpressure passes outwardly through the ports 26 that open through thebody 1% into the interior of the packing 25 between its lip seals 27.Fluid under pressure inflates and elongates the packing sleeve 25 andurges the upper expander 13 upwardly, disrupting the shear screws 14,and shifting the upper expander 13 within the slips. This action slidesthe latter radially outward along the abutment ring 16, as guided by theslidable pins 17 and slots 18, and into engagement with the wall of thewell casing B (see Fig. 2). The lower shear screws 21, 22 have asubstantially greater shear value than the upper shear screws 14, 15,which insures disruption of the latter under the action of the fluidpressure, as described above, while the lower shear screws 21, 22 remainintact.

After the upper slips 12 have been expanded against the casing 13, anupward strain may be taken on the tubing string C, which shifts thepacker body 10 upwardly within the upper conical expander 13 and carriesthe lower expander 21) and slips 19 upwardly with the body. This actionforeshortens and compresses the packing sleeve 25 and expands itoutwardly into sealing engagement with the wall of the well casing B. Acontinuation of the upward strain then disrupts the lower shear screws21, 22, which allows the lower abutment 23, 24 to shift the lower slips19 upwardly along the lower expander and radially outward into anchoringengagement with the well casing B (Fig. 3). All of the parts are held inthe position to which they have been expanded, and are prevented frommoving to retracted position, by a suitable lock ring which maybe in theform of a split, contractile element 38 retained within a groove 39 inthe upper expander 13 and adapted to engage the downwardly facingratchet teeth 40 formed on the exterior of the packer body 11).

After the packer A has been anchored in packed-off condition against thewall of the well casing B, the pressure can be increased to shear thescrew 33 holding the trip ball seat 32 to the valve housing 24, whichenables the seat to be blown out of the valve housing and removes thearm 34 from its holding position against the ball valve element 35,allowing the latter to shift upwardly into engagement with the valveseat 36, in the event that reverse flow through the well packer tends tooccur.

It is to be noted that the shear screws 15 normally or initially retainthe upper slip segments 12 in their retracted position, and also intransverse alignment with respect to one another. In addition, the guidepins 17 in the abutment 16 are then properly disposed within thetransverse slip slots 18. However, upon the shearing of the screws 15attaching the slips 12 to the upper conical expander 13, assurance isnot had that this transverse alignment of the slip segments 12 withrespect to each other, and the engagement of the slips 12 with the lowersurface of the abutment ring 16 will be maintained. Disruption of theshear screws 15 might allow one or more of the slip segments 12 to dropdownwardly along the packer body 10 and also along the conical expander13, to shift one or more of the slip segments out of engagement with theabutment ring 16. The extent of downward dropping of one or more of theslip segments 12 may be sufficient to remove the slip slot or slots 18from a position receiving the associated guide pin or pins 17 secured tothe abutment ring 16.

As a result of the disalignment between the slip segments 12, they donot engage the tapered expander sur face 28 along the same relativeportion. A slip segment 12 that may have dropped downwardly along theexpander 13 a greater distance than another slip segment will ob:viously engage the well casing and will cock or shift the expander 13andthe packer body 19 (and for that matter the entire well packer) into aposition that is no longer coaxial with the well casing B in which thewell packer A is located. This action not only will result in the lackof coaxiality, but it will subject the well packer to bending strainsthat may produce its failure, particularly since it is common practiceto make the packer body 10 of cast magnesium or cast aluminum,particularly in the event it is desired to disintegrate or otherwisedrill out the well packer at a later date.

The present invention seeks to overcome the aforenoted difliculties. Theupper segmental slips 12 are pro,- vided collectively with an internalcircumferential groove 50, the groove portions of the slips lying in acommon transverse plane that is normal to the axis of the well packer.Disposed within the circumferential groove 50, that is common to all ofthe slip segments 12, is a ring 51 which bridges the spaces or gaps 52between the slip segments 12. This ring 51 is split and tends tocontract into frictional engagement with the periphery of the packerbody 10. By virtue of this frictional engagement, the ring holds theslip segments 12 in an upward position, with their upper surfaces inengagement with the lower surface of the abutment ring 16. Accordingly,when the packing sleeve 25 is inflated, for the purpose of expanding theupper slip segments 12 outwardly against the well casing B, such actionshears the screws 14, 15 and releases the slip segments 12 from theupper expander 13 (Fig. 2). However, upon disruption of the slip screws15, the slips 12 cannot drop downwardly along the expander 13 and thebody 10, in view of. the frictional engagement of the aligning ring 51with the periphery of the packer body 10. Accordingly, the expander 13moves upwardly within the slips 12 and slides the latter along theundersurface of the abutment ring 16 and radially outward into firmanchoring engagement with the wall of the well casing B.

The pressure normally imposed within the packing sleeve 25 for shiftingthe upper expander 13 upwardly within the slips 12 is sufiiciently greatas to firmly wedge the expander within the slips and dig the slipwickers 53 into anchoring engagement with the well casing, in whichposition the slips will remain.

It is, accordingly, apparent that the aligning ring 51 not onlymaintains the slip segments 12 in transverse alignment with respect toone another while they are being expanded outwardly into engagement withthe wall of the well casing B, but it also holds the slip segments 12 inan upward position against the abutment ring 16, which is highlydesirable. This upward maintenance of the slip segments against theabutment ring also insures that the guide slots 18 in the slip segmentswill remain in a position to fully receive the guide pins 17. Theretention of the guide pins 17 in these slots 18 will cause the slipsegments to be shifted radially outward, to maintain the angulardisposition between the slip segments 12 uniformly around the body 10 ofthe well packer (Fig. 6). As a resuit, assurance is had that the slipsegments will engage the well casing B and the expander wedgedtherewithiu in such position as to center and maintain the packerbodyll) coaxially of the well conduit B. During the outward expansion ofthe slip segments 12, the split ring bridges the gaps 52 between thesegments themselves, and maintains the latter in the desiredtransversely aligned relationship.

The internal circumferential groove 50 in the slip segments 12 and thering 51 therewithin that frictionally engages the periphery of thepacker body 10 are disposed initially a substantial distancelongitudinally away from the near or small end 13a of the expander 13.In the specific exemplification of the invention shown in the drawings,the ring 51 and slip groove 50 are disposed a substantial distance abovethe smaller end 13a of the upper expander. This distance is provided toinsure the movement of the expander 13 within the slip segments 12 whilethe latter are being expanded outwardly, with free: 10m. nl intsri rensr m the n 5 itself- In s casing sizes having a relatively large insidediameter, such as lightweight casing, a situation might develop in whichthe smaller end 13a of the expander may engage the split aligning ring51. However, the parts are so related to one another that just beforesuch engagement can occur, the slips 12 will have moved laterallyoutwardly to an extent sufilcient to completely shift the segments 12off thealigning ring 51. Accordingly, the end of the expander 13a willthen engage the ring 51 and shift the ring with it longitudinally of thebody 10, this shifting action being without interference from the slips(see Fig. 4).

The operation just described may only occur in comparatively. rareinstances, and when it does occur the slips 12 only have a comparativelysmall lateral distance left ,to travel before their wickers 53 areengaged with the wall ofthe well casing B. Accordingly, under thoseextreme conditions, the slips 12 could only move relatively downwardalong the body after having become disengaged from the alignment ring avery small distance, which, as a practical matter, is insufiicient toproduce any substantial transverse disalignment between the segments 12before they are-wedged into anchoring engagement with the wall of thewell casing. In addition, the distance that these segments have to movetransversely outward into engagement with the well casing isinsuflicient to permit the segments to drop downwardly with respect tothe abutment ring 16, so as to bring the slotted slip portions out ofenclosing engagement with respect to the guide pins 17.

From the foregoing description, it is apparent that an aligning ringarrangement has been provided which does not interfere with outwardexpansion of the slip segments 12 into engagement with the well casing Bafter the retaining screws 15 have been disrupted. The aligning devicekeeps the segments in transverse alignment with respect to each otherwhile maintaining them in upward position against the abutment ring 16,in which position the slips are properly coordinated with respect to theguide pin 17. so as to insure their arcuatedisplacement with respect toeach other when they are in firm anchoring engagement with the wall ofthe well casing B.

The inventor claims:

l. A well too], including a body adapted to be lowered in a well conduiton a running-in string, means for anchoring said body to the wellconduit comprising a set of initially retracted segmental slips havingan internal circumferential groove therein, an expander slidable on saidbody and along and within said slips to. expand said slips outwardlyinto engagement with the well conduit, and an annular member movablelongitudinally with respect to said body and disposed in said grooveduring outward expansion of said slips to maintain said segmental slipsin transverse alignment with respect to each other.

2. A well tool, including a body adapted to be lowered in a well conduiton a running-in string, means for anchoring said body to the wellconduit comprising a set of initially retracted segmental slips havingan internal circumferential groove therein and expandible outwardly intoengagement with the well conduit, and an annular member movablelongitudinally with respect to said body and disposed in said grooveduring outward expansion of said slips and frictionally engaging saidbody to maintain said segmental slips in transverse alignment withrespect to each other and to resist movement of said slipslongitudinally of said body, while permitting said body to movelongitudinally of said slips after said slips have engaged the wellconduit.

3. A well tool, including a body adapted to be lowered in a well conduiton a running-in string, an abutment on said body, means for anchoringsaid body to the well conduit comprising an expander on said body and aset of segmental slips engaging said expander, means for shifting saidexpander along said body and slips to shift said slips along saidabutment outwardly into engagement with the well conduit, said set ofslips having an internal circumferential groove therein, and an annularand disposed in said groove'during outward movement of said slips intoengagement with the well conduit to maintain said slips in transversealignment with respect to each other during their outward movement intoengagement with the well conduit.

4. A well tool, including a body adapted to be lowered in a well conduiton a running-in string, an. abutment on said body, means for anchoringsaid body to the well conduit comprising an expander on said body and aset of segmental slips engaging said expander, means for shifting saidexpander and slips longitudinally with respect to each other to shiftsaid slips transversely along said abutment outwardly into engagementwith the well conduit, said set of slips having an internalcircumferential groove therein, and an annular member movablelongitudinally with respect to said body and disposed in said grooveduring outward movement of said slips into engagement with the wellconduit to maintain said slips in transverse alignment with respect toeach other during their outward movement into engagement with the wellconduit.

5. A well tool, including a body adapted to be lowered in a well conduiton a running-in string, an abutment on said body, means for anchoringsaid body to the well conduit comprising an expander on said body and aset of segmental slips engaging said expander, means for shifting saidexpander and slips longitudinally with respect to each other to shiftsaid slips transversely along said abutment outwardly into engagementwith the well conduit, said set of slips having an internalcircumferential groove therein, and an annular member movablelongitudinally with respect to said body and disposed in said grooveduring outward movement of said slips into engagement with the Wellconduit and frictionally engaging said body to maintain said segmentalslips in transverse alignment with respect to each other and to resistmovement of said slips longitudinally of said body, while permittingsaid body to move longitudinally of said slips after said slips haveengaged the well conduit.

6. A well tool, including a body adapted to be lowered in a well-conduiton a running-in string, an abutment on said body, means for anchoringsaid body to the well conduit comprising an expander on said body and aset of segmental slips engaging said expander, means for shifting saidexpander and slips longitudinally with respect to each other to shiftsaid slips transversely along said abutment outwardly into engagementwith the well conduit, interengageable means on said abutment and slipsfor guiding said slips generally radially outwardly along said abutment,said set of slips having an internal circumferential groove therein, andan annular member movable longitudinally with respect to said body anddisposed in said groove during outward movement of said slips intoengagement with the well conduit and fric tionally engaging said body.

7. A well tool, including a body adapted to be lowered in a well conduiton a running-in string, an abutment on said body, means for anchoringsaid body to the well conduit comprising an expander on said body and aset of segmental slips engaging said expander, means for shifting saidexpander along said body and slips toward said abutment to shift saidslips along said abutment outwardly into engagement with the wellconduit, interengageable means on said abutment and slips for guidingsaid slips generally radially outward along said abutment, said set ofslips having an internal circumferential groove therein, and an annularmember movable longitudinally with respect to said body and disposed insaid groove during outward movement of said slips into engagement withthe well conduit and frictionally engaging said body.

8. A well tool, including a body adapted to be lowered in a well conduiton a running-in string, an abutment fixed to said body, means foranchoring said body to the well conduit, comprising an expander slidableon said body and a set of segmental slips engaging said expander and'thelower surface of said abutment, means for shifting said expanderupwardly along said body and slips and towards said abutment to shiftsaid slips along said abutment outwardly into engagement with the Wellconduit, said set of slips having an internal circumferential groovetherein, and an annular member movable longitudinally with respect tosaid body and disposed in said groove during outward movement of saidslips into engagement with the well conduit and frictionally engagingsaid body.

9. A well tool, including a body adapted to be lowered in a well conduiton a running-in string, an abutment fixed to said body, means foranchoring said body to the well conduit, comprising an expander slidableon said body and a set of segmental slips engaging said expander and thelower surface of said abutment, means for shift ing said expanderupwardly along said body and slips toward said abutment to shift saidslips along said abutment outwardly into engagement with the wellconduit, interengageable means on said abutment and slips for guidingsaid slips generally radially outward along said abutment, said set ofslips having an internal circumferential groove therein, and an annularmember movable longitudinally with respect to said body and disposed insaid groove during outward movement of said slips into engagement withthe well conduit and frictionally engaging said body.

10. A well tool, including a body adapted to be lowered in a wellconduit on a running-in string, an expander on said body having acircumferentially continuous ex; ternal expander surface; a set ofsegmental slips -engage able with said expander surface for anchoringsaid body in a well bore, frangible means initially securing said slipsin retracted position with respect to said body and expander, means forrelatively moving said slips and expander to disrupt said frangiblemeans and shift said slips outwardly into engagement with the wellconduit, said set of slips having an internal circumferential groovetherein, and an annular member movable longitudinally with respecttosaid body and disposed in said groove during outward movement of saidslips to maintain said slips in transverse alignment with respect toeach other following disruption of said frangible means and duringoutward movement of said slips into engagement with the well conduit.

References Cited in the file of this patent UNITED STATES PATENTS909,609 Kesselman Jan. 12, 1909 1,118,538 Driscoll Nov. 24, 19141,815,376 Jones July 21, 1931 2,187,482 Baker et al. Jan. 16, 19402,241,532 Barnes May 13, 1941 2,248,211 Young July 8,.1941 2,368,409Burt Jan. 30, 1945 2,383,453 Crickmer Aug. 28, 1945

1. A WELL TOOL, INCLUDING A BODY ADAPTED TO BE LOWERED IN A WELL CONDUITON A RUNNING-IN STRING, MEANS FOR ANCHORING SAID BODY TO THE WELLCONDUIT COMPRISING A SET OF INITIALLY RETRACTED SEGMENTAL SLIPS HAVINGAN INTERNAL CIRCUMFERENTIAL GROOVE THEREIN, AN EXPANDER SLIDABLE ON SAIDBODY AND ALONG AND WITHIN SAID SLIPS TO EXPAND SAID SLIPS OUTWARDLY INTOENGAGEMENT WITH THE WELL CONDUIT, AND AN ANNULAR MEMBER MOVABLELONGITUDINALLY WITH RESPECT TO SAID BODY AND DISPOSED IN SAID GROOVEDURING OUTWARD EXPANSION OF SAID SLIPS TO MAINTAIN SAID SEGMENTAL SLIPSIN TRANSVERSE ALIGNMENT WITH RESPECT TO EACH OTHER.